Data from: Distinguishing the victim from the threat: SNP‐based methods reveal the extent of introgressive hybridization between wildcats and domestic cats in Scotland and inform future in situ and ex situ management options for species restoration

The degree of introgressive hybridisation between the Scottish wildcat and domestic cat has long been suspected to be advanced. Here we use a 35-SNP-marker test, designed to assess hybridisation between wildcat and domestic cat populations in Scotland, to assess a database of 265 wild-living and captive cat samples, and test the assumptions of the test using 3097 SNP markers generated independently in a subset of the data using ddRAD. We discovered that despite increased genetic resolution provided by these methods, wild-living cats in Scotland show a complete genetic continuum or hybrid swarm structure when judged against reference data. The historical population of wildcats, although hybridised, clearly groups at one end of this continuum, as does the captive population of wildcats. The interpretation of pelage scores against nuclear genetic data continues to be problematic. This is probably because of a breakdown in linkage disequilibrium between wildcat pelage genes as the two populations have become increasingly mixed, meaning that pelage score or SNP score alone are poor diagnostic predictors of hybrid status. Until better tools become available, both should be used jointly, where possible, when making management decisions about individual cats. We recommend that the conservation community in Scotland must now define clearly what measures are to be used to diagnose a wildcat in the wild in Scotland, if future conservation action is to be effective.

长久以来，学界普遍怀疑苏格兰野猫与家猫之间的基因渐渗杂交（introgressive hybridisation）程度较高。本研究利用一套专为评估苏格兰野猫与家猫种群间杂交情况设计的35个单核苷酸多态性（Single Nucleotide Polymorphism, SNP）标记检测体系，对包含265份野生及圈养猫样本的数据库开展分析，并通过ddRAD技术在数据集子集上独立获得的3097个SNP标记，对该检测体系的假设前提进行验证。
研究发现，尽管上述方法提升了遗传分辨率，但对照参考数据来看，苏格兰野生猫群呈现出完整的遗传连续体（genetic continuum）或杂交集群（hybrid swarm）结构。尽管已发生杂交，但历史上的苏格兰野猫种群与圈养野猫种群一样，均明确聚类于该遗传连续体的一端。
基于核遗传数据解读皮毛评分的方式仍存在局限性。这可能是由于随着两个种群的不断混合，野猫皮毛相关基因间的连锁不平衡（linkage disequilibrium）已被打破，这意味着仅依靠皮毛评分或SNP评分均无法准确预测个体的杂交状态。在开发出更优异的检测工具之前，若要针对个体野猫制定管理决策，应尽可能同时结合这两项指标进行综合判断。
我们建议，若要确保苏格兰未来的野猫保护行动取得实效，当地保护学界必须尽快明确界定用于野外鉴定苏格兰野猫的具体标准。